A New Flexure Revolute Joint with Leaf springs and Its Application to Large Workspace Parallel Robot

Abstract

This paper presents a flexure revolute joint with a large range of motion which can be used as a joint in a parallel robot with a large workspace. We proposed a new structure of flexure revolute joint. The joint consists of leaf springs which are symmetrically arranged between two frames. The shape of the frame is like a spiral stairs. Arrangement of leaf springs was proposed taking into consideration the axis drift and stiffness characteristics of the joint while achieving a large range of motion. Characteristics of the proposed joint were investigated by Finite Element Analysis (FEA) and experiments. A planar parallel robot with two degrees of freedom using the proposed joints was designed and fabricated. Its workspace, position repeatability and stiffness were experimentally investigated.